JPH04270611A - Resin molding device - Google Patents

Abstract

PURPOSE:To provide a resin molding device having no such fear that in the case where the primary product is molded by a high-pressure IMC method by setting up SNC into two product molding of a bottom force by splitting the SMC and giving pressure, a porosity may be generated in a meeting part off the SMC, an injected IMC material may be filled into the porosity after molding of the primary molded product and forming of a uniform IMC layer may become difficult. CONSTITUTION:A vacuum suction hole 11 is provided in a bottom force 5 of a part where SMC 30 is to meet, pressure sensors 12, 12 are provided in the vicinity of the vacuum suction hole 11 and air is sucked through the vacuum suction hole 11 unite the SMC 30 is detected by the pressure sensors 12, 12 or the air is held within a groove 40 by providing the groove 40 in the bottom force 5 the meeting part of the SMC 30. A number of porosities to be formed in the meeting part of the SMC is reduced drastically and then an IMC material is injected.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a resin molding apparatus, and more specifically, after pressure molding a sheet molding compound, injecting an in-mold coating material into a mold to form a sheet. - It relates to a device that applies an in-mold coating layer to the surface of a primary molded product of a molding compound and molds two resin molded products in one molding.

0002

[Prior art] Thermosetting resin such as unsaturated polyester,
Sheet molding compound consisting of glass fiber and fillers such as calcium carbonate
Molding Compound: Hereinafter referred to as “SMC
” is abbreviated as “. ) in a mold heated to a predetermined temperature, the obtained primary molded product is held in the mold, and a thermosetting resin such as unsaturated polyester is injected into the mold, In-mold coating (
In-Mold Coating: Hereinafter referred to as "IMC"
It is abbreviated as. ) A resin molding method called the in-mold coating method is known, in which a resin molded product is obtained by applying a layer.

[0003] Generally, when a molded product made of SMC is pressure-molded, a large number of small porosity are often formed inside the product, filled with air or gas from volatile components in the SMC. If such porosity exists, when baking or painting a molded product made of SMC, the gas in the porosity expands or pushes up the formed coating film due to baking after the coating film is formed. It is also known that the IMC layer breaks through the formed coating film and causes defects in the coating film, and the IMC layer is
By covering the surface of a molded product made of porosity, the gas within the porosity is contained, thereby preventing defects in the coating film from occurring.

However, in the conventional IMC method, after pressure forming a molded product made of SMC, the upper mold is lifted and a gap is created between the lower surface of the upper mold and the upper surface of the molded product made of SMC. After forming the IMC material, an IMC material made of a thermosetting resin such as unsaturated polyester is injected into the gap and pressurized again. Therefore, when the IMC material is injected, the air in the gap is There is a problem in that it may penetrate into the interior and form a large number of small porosity, making it impossible to effectively prevent the defects in the coating film described above.

[0005] Therefore, in order to prevent the formation of porosity during injection of such IMC materials, in recent years, after pressure molding of molded products made of SMC, the upper mold is held as it is without lifting it. A method called a high-pressure in-mold coating method has been proposed in which high-pressure IMC material is injected into a mold to prevent the formation of porosity during injection of the IMC material. According to this high-pressure in-mold coating method, the IMC material is injected while compressing the SMC to form the IMC.
No porosity is formed inside the MC layer, and S
The gas in the porosity inside the molded product made of MC is
The MC layer can completely confine the gas inside the porosity, and even when baking paint is applied, a coating film is formed on the surface of the IMC layer and baked, so the gas inside the porosity is cured. The IMC layer makes it possible to completely encapsulate and prevent defects from forming in the coating.

[0006]

[Problems to be Solved by the Invention] When molding resin molded products using such a high-pressure in-mold coating method, in order to reduce molding costs and mold manufacturing costs, two As the product is shaped,
A gate part for injecting the IMC material is formed between the product parts that will become the final product, and the SMC is divided into two parts, set, and processed in the product molding part of the lower mold that molds the product part. A primary molded SMC product is molded so that the divided and set SMCs join together to form a gate part under pressure, and then, toward the gate part located in the center of the primary molded product, It is possible to inject the IMC material, but in this way, the SMC is divided and set in the two product molding parts of the lower mold, and the divided SMC is merged.
When pressurizing and molding a primary molded SMC product to form a gate part, air is pushed out together with the SMC toward the gate part as a result of the pressurization, and as a result, the confluence part When the IMC material is injected under high pressure, the IMC material is filled into these porosity and is consumed, forming a primary material made of SMC. There was a problem in that an IMC layer could not be formed as desired on the surface of a molded article.

[0007]

Purpose of the Invention The present invention provides an I
A resin molding device that injects a MC material to mold a resin molded product, and is capable of forming an IMC layer economically and as desired on the surface of a primary molded product made of the SMC. The purpose is to provide a device.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a gate molding section that molds a gate section to be cut after molding a resin molded product, and an SMC set on both sides of the gate molding section to form a product section. Equipped with two product molding sections for molding,
By providing an IMC material injection means in the gate molding part, and providing a porosity generation prevention means in the gate molding part of the lower mold near the part where the SMC set in the two product molding parts should join. achieved.

In a preferred embodiment of the present invention, the SM is placed in the gate molding section of the lower mold near the part where the SMCs set in the two product molding sections are to join.
A pressure reducing means is provided for reducing the pressure of the portion where C is to join. In another preferred embodiment of the invention,
A groove portion is formed in the gate molding portion of the lower die near a portion where the SMC set in the two product molding portions should merge.

0010

According to the present invention, since the porosity generation prevention means is provided in the gate molding section of the lower die where porosity is likely to occur, where the SMCs set in separate sections should merge, the porosity generation preventing means is provided. The occurrence of a large number of relatively large porosity can be reliably prevented, and therefore, at high pressure, the injected IMC material is filled into the porosity formed at the confluence of the SMC, It is not consumed, and it becomes possible to form an IMC layer as desired on the surface of a primary molded product made of SMC. Furthermore, since two products can be molded in one molding process, it is possible to significantly reduce the manufacturing cost of resin molded products.

According to a preferred embodiment of the present invention, a pressure reducing means is provided in the gate molding section of the lower mold where porosity is likely to occur where the divided and set SMCs should join together, so that by applying pressure, Together with the SMC, the air pushed out toward the part where the SMC should merge can be removed from the space between the upper mold and the lower mold by this decompression means, and a large number of It is now possible to reliably prevent relatively large porosity from occurring, and therefore, at high pressure, the injected IMC material
It is filled into the porosity formed at the confluence of SMC and is not consumed, making it possible to form an IMC layer as desired on the surface of a primary molded product made of SMC, and Since two products can be molded in one molding process, the manufacturing cost of resin molded products can be significantly reduced.

According to another preferred embodiment of the invention,
A groove is formed in the gate molding part of the lower die where porosity is likely to occur, where the SMC set in sections should merge, and when pressurized, the SMC is pushed out along with the SMC towards the part where it should merge. Since the injected air is accommodated in this groove, it is possible to reliably prevent the occurrence of a large number of relatively large porosity at the confluence of SMC, and therefore, the injected IMC material is , S
It is filled into the porosity formed at the confluence of MC and is not consumed, making it possible to form an IMC layer as desired on the surface of a primary molded product made of SMC, and Since two products can be molded in one molding process, the manufacturing cost of resin molded products can be significantly reduced.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic diagram of a resin molding apparatus according to an embodiment of the present invention, FIG. 2 is a schematic enlarged cross-sectional view of the vicinity of an IMC material injection part of a resin molding apparatus according to an embodiment of the present invention, and FIG. 3 is a schematic diagram of a resin molding apparatus according to an embodiment of the present invention. FIG. 4 is a schematic plan view of the lower die showing the set state, and FIG. 4 is a schematic side view of the resin molded product.

[0014] The resin molding apparatus according to the embodiment of the present invention includes 1
The structure is such that two products can be molded in one molding process, and as shown in Figure 4, the molded resin molded product 1
is provided with product parts 2, 2 that will become the final resin molded product, and a gate part 3 that is located between the product parts 2, 2 and is removed after molding. In FIG. 1, the resin molding apparatus according to the embodiment of the present invention includes an upper mold 4 and a lower mold 5.
Approximately in the center of the IMC is an IMC that injects the IMC material supplied from the IMC material supply device 6 between the upper mold 4 and the lower mold 5.
A material injector unit 7 is provided.

As shown in FIG. 2, a pipe 8 is provided at a position facing the IMC material injector unit 7 of the lower mold 5.
is connected to the vacuum pump 9 by the shutoff pin 10.
A vacuum suction hole 11 that can be opened and closed is formed by
A pair of pressure sensors 1 are installed on both sides near the vacuum suction hole 11.
2 and 12 are provided. The shutoff pin 9 opens when air is supplied from the piping 13, and the vacuum suction hole 11 opens.
The pipe 8 connected to the vacuum pump 9 communicates with the upper mold 4.
It is configured to suck air in the space between the mold 5 and the lower mold 5, and close when air is supplied from the pipe 14. FIG. 2 shows a state in which the shutoff pin 9 is closed and communication between the vacuum suction hole 11 and the vacuum pump 9 is cut off, and the pipes 13 and 14 are omitted from FIG. 1.

[0016] Also, IMC material injector unit 7
is equipped with a nozzle 16, and is driven by an injector drive means 15, and includes a shutoff pin 18 for communicating between the nozzle 16 and a piping 17 connected to the IMC material supply device 6, or for cutting off communication between them. ing. Furthermore, a control unit 20 is provided, and the control unit 20 outputs a pressure control signal to the pressure control means 21 to control the hydraulic pressure of the upper mold drive means 22 that hydraulically drives the upper mold 4. At a predetermined timing, the vacuum pump 9 is driven, and the IMC material is supplied from the IMC material supply device 6 to the IMC material injector unit 7. Furthermore, control unit 2
0 supplies air to the piping 13 at a predetermined timing to open the shutoff pin 9, and also opens the pressure sensor 12.
, 12, when the pressure detection value of either of the pair of pressure sensors 12, 12 increases, the supply of air from the pipe 13 is cut off, and the pipe 1
4 and controls the opening and closing of the shut-off pin 9 so as to close the shut-off pin 9. Furthermore, a drive signal is output to the injector drive means 15 at a predetermined timing to cause the nozzle 16 to close. The IMC material supply device 6 and the connected piping 17 are controlled to communicate with each other, or to cut off the communication between them.

As shown in FIGS. 1 and 3, the SMC
Prior to the molding of the primary molded product consisting of the following, the SMC 30 is divided into two parts each having a predetermined number and set in the product molding section of the lower die 5 where the product parts 2, 2 are to be molded. After that, the upper mold 4 is lowered by the upper mold driving means 22, and the SMC 30 is moved by the upper mold 4 under a predetermined pressure.
Pressurized. As a result, the SMC 30 set separately on the lower die 5 flows toward the gate forming section where the gate section 3 is formed, but as the SMC 30 flows, air also flows toward the gate forming section. and is pushed out. Here, at the start of molding of the primary molded product made of SMC 30, the shutoff pin 10 is open, so that the piping 8 communicating with the vacuum suction hole 11 and the vacuum pump 9 is opened.
are in communication and air is sucked from the vacuum suction hole 11, so as the SMC 30 flows, the pushed out air is sucked from the vacuum suction hole 11 to the vacuum pump 9.
It is removed from the space between the upper mold 4 and the lower mold 5.

[0018] Then, when the SMC 17 flows onto one of the pair of pressure sensors 12, 12 and the pressure detection value detected by one of the pressure sensors 12 increases, the control unit 20 controls the pressure sensor 12. Based on the pressure detection signal from the pipe 12, the air supply from the pipe 13 is cut off, air is supplied to the pipe 14, and the shutoff pin 9 is closed. After that, SMC30 merges with SMC
A primary molded product consisting of Here, the pair of pressure sensors 12, 12 are provided near the vacuum suction hole 11, so when the air suction is finished, the amount of air that flows between the SMCs 30 from both sides is very small. can be,
Therefore, after that, SMC30 joins and SMC
Even when a primary molded product consisting of SMC30
Almost no porosity is formed at the confluence of the two. Therefore, after that, the control unit 20
The IMC material is supplied from the IMC material supply device 6 to the IMC material injector unit 7 , and a drive signal is output to the injector drive means 15 to drive the nozzle 16 .
and piping 17 are communicated with each other, and the IMC material flows through the nozzle 16.
Therefore, even if the IMC material is injected into a primary molded product made of SMC30, the amount of IMC material consumed by filling the porosity formed at the confluence of SMC30 is very small. It becomes possible to form a uniform IMC layer on the surface of the primary molded product as desired. Thus, when the IMC layer is formed and cured,
The resin molded product 1 is taken out from the upper mold 4 and the lower mold 5,
The gate part 3 is cut and the product parts 2 and 2 corresponding to the product parts 2 and 2 are cut.
One final product is obtained.

FIG. 5 is a schematic side view of a lower mold 5 used in a resin molding apparatus according to another embodiment of the present invention. In this embodiment as well, the SMC 30 is divided into two parts each having a predetermined number of sheets and set in the product forming section where the product parts 2, 2 of the lower mold 5 are molded. 4, the SMC30 is divided and set by being pressurized.
The two converge at the gate forming part where the gate part 3 is formed. As shown in FIG. 5, in this example,
In FIG. 5, a groove 40 extending in a direction perpendicular to the paper surface is formed in a portion of the lower mold 5 where the SMC 30 is to join. Therefore, in the process of being pressurized by the upper mold 4 and molding a primary molded product made of SMC 30, the portion of the SMC 30 set in sections where the gate portion 3 will be formed, as in the above embodiment, is As a result, SMC
The air pushed out toward the confluence of SMC
30, the SMC 30 is pushed into the groove 40 formed in the portion to be merged and is accommodated therein. In this way, since the air is exclusively accommodated in the groove 40, the relatively large porosity that was conventionally formed at the convergence part of the SMC30 is hardly formed, and therefore, the primary molded product made of the SMC30 is molded. Later, IM
Even if the C material is injected from the nozzle 16 toward the primary molded product made of SMC, the amount of IMC material consumed by filling the porosity formed at the confluence of the SMC 30 is very small. Therefore, it becomes possible to form a uniform IMC layer as desired on the surface of a primary molded product made of SMC30. In this way, an IMC layer is formed,
After curing, the resin molded product 1 is taken out from the upper mold 4 and lower mold 5, the gate part 3 is cut, and the product parts 2, 2 are removed.
Two final products are obtained corresponding to .

[0020] The present invention is not limited to the above-mentioned embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included within the scope of the present invention. Needless to say, this is something that will be done. for example,
In the embodiment shown in FIGS. 1, 2, and 4, a pair of pressure sensors 12, 12 are provided near the vacuum suction hole 11 and on both sides thereof to detect the flow state of the SMC 30. However, the sensor is not limited to the pressure sensors 12, 12, and any sensor can be used as long as it can detect the SMC 30.

Further, in the embodiments shown in FIGS. 1, 2, and 4, a pair of pressure sensors 12, 12 are provided, but the number of pressure sensors 12, 12 is limited to two. It is not limited to 2 or more, but can be arbitrarily selected as long as it is 2 or more.

[0022]

Effects of the Invention According to the present invention, a resin molding apparatus for molding a resin molded product by injecting an IMC material onto the surface of a primary molded product made of SMC by a high-pressure in-mold coating method can be used economically. In addition, it is possible to provide a resin molding apparatus that can form an IMC layer as desired on the surface of a primary molded product made of the SMC.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a resin molding apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic enlarged sectional view of the vicinity of the IMC material injection part of the resin molding apparatus according to the embodiment of the present invention.

FIG. 3 is a schematic plan view of the lower mold showing a state in which the SMC is set.

FIG. 4 is a schematic side view of a molded resin product.

FIG. 5 is a schematic side view of a lower die of a resin molding apparatus according to another embodiment of the present invention.

[Explanation of symbols]

1 Resin molded product 2 Product Department 3 Gate part 4 Upper mold 5 Lower mold 6 IMC material supply device 7 IMC injector unit 8, 13, 14, 17 Piping 9 Vacuum pump 10, 18 Shutoff pin 11 Vacuum suction hole 12 Pressure sensor 15 Injector drive means 16 Nozzle 20 Control unit 21 Pressure control means 22 Upper mold drive means 30 SMC 40 groove

Claims (3)

[Claims] 1. In a resin molding device that injects an IMC material onto the surface of a primary molded product made of SMC to form a resin molded product using a high-pressure in-mold coating method, the resin molded product is cut after being molded. A gate molding part for molding a gate part, and two product molding parts each having an SMC set on both sides of the gate molding part to mold a product part, and an IMC material injection means in the gate molding part. A resin molding apparatus characterized in that a porosity generation prevention means is provided in the gate molding part of the lower mold near the part where the SMCs set in the two product molding parts are to join. 2. A depressurizing means is provided in the gate molding section of the lower mold near a portion where the SMC set in the two product molding sections is to merge, for reducing the pressure in the portion where the SMC is to merge. The resin molding apparatus according to claim 1, characterized in that: 3. The resin according to claim 1, wherein a groove portion is formed in the gate molding portion of the lower mold near a portion where the SMCs set in the two product molding portions are to join. Molding equipment.